Event Handling Issues

Question

Hi Guys..
I am doing some event handling code and am having some problem.I have placed the following on the stage, a submit button whose instance name is 'btnSubmit' and a label whose instance name is 'lblTest'. The ActionScript 3 code resides in a separate 'Maxwell.as' file. In the 'Maxwell.FLA'
file, I have typed 'Maxwell' in the document class property. The following is my AS3 code:
package
import flash.display.Sprite;
import flash.events.MouseEvent;
public class Maxwell extends Sprite
  public function Maxwell()
   // constructor code
  private function sendMsg(e:MouseEvent):void
   lblTest.text = "Clicked";
  btnSubmit.addEventListener(MouseEvent.CLICK, sendMsg);
When I do a 'CNTRL + ENTER' and run this program I get the following errors:
Access of undefined property btnSubmit.
Access of undefined property sendMsg.
I don't understand why I am getting these errors. I have already linked up both files by typing 'Maxwell' in the
document class window and furthermore 'sendMsg' is the name of a function. I hope somebody can advise me. Thanks.

Answer 1

Your add listener code is outside any function - you can't do that with classes. You can put it in the constructor:
package
import flash.display.Sprite;
import flash.events.MouseEvent;
public class Maxwell extends Sprite
  public function Maxwell()
   // constructor code
      btnSubmit.addEventListener(MouseEvent.CLICK, sendMsg);
  private function sendMsg(e:MouseEvent):void
   lblTest.text = "Clicked";